Maine was pretty close for Carter in '80, much closer than Vermont and New Hampshire. Maine likes moderate Republicans; Reagan is clearly not that. You could be right though, the VP factor makes this hazy. But I think Maryland is more likely than Maine. Wallace got 10% there, and Reagan just needs a fraction of that to put him over the top.
The scenario I hypothesized above is a Reagan landslide, and bear in mind Maryland ONLY goes for the GOP in landslides (1972, 1984, 1988). So if Maine goes to the Democrats, then probably so does Maryland.